In 1997 Minkiewicz contributed to the science of software measurement by proposing predictive object points ( POPs ) as a means of measuring three characteristics of object-oriented software ( combined data and functions, object communication and reuse via software.
22.
If only one image is available, it is impossible to determine the spatial X, Y, Z position of such object points, because the simple direction is insufficient : all the points along that direction would give the same image point.
23.
This reduced rank of measurement matrix can be motivated from the fact that, the position of the projection of an object point on the image plane is constrained as the motion of each point is globally described by a precise geometric model.
24.
If the object point be infinitely distant, all rays received by the first member of the system are parallel, and their intersections, after traversing the system, vary according to their " perpendicular height of incidence, " i . e . their distance from the axis.
25.
Lenses suffer from aberrations that distort images . " Monochromatic aberrations " occur because the geometry of the lens does not perfectly direct rays from each object point to a single point on the image, while chromatic aberration occurs because the index of refraction of the lens varies with the wavelength of the light.
26.
The virtual image of the aperture as seen from the world is known as the lens's entrance pupil; ideally, all rays of light leaving a point on the object that enter the entrance pupil will be focused to the same point on the image sensor / film ( provided the object point is in the field of view ).
27.
We receive, therefore, in no single intercepting plane behind the system, as, for example, a focusing screen, an image of the object point; on the other hand, in each of two planes lines O'and O " are separately formed ( in neighboring planes ellipses are formed ), and in a plane between O'and O " a circle of least confusion.
